Body portal anchors and systems

ABSTRACT

Anchors for securing a therapy device such as a therapy catheter relative to a burr hole, and systems and methods for using the same. Anchors in accordance with embodiments of the present disclosure may include a connector for securing the therapy catheter to a delivery catheter, wherein the connector is independently and removably attachable to the anchor. The connector may secure the therapy catheter relative to the burr hole and isolate forces that may otherwise tend to disrupt the placement of the therapy catheter.

RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional App. No.61/328,855, filed Apr. 28, 2010, the content of which is incorporatedherein by reference.

TECHNICAL FIELD

Embodiments of the present invention relate generally to medical devicesand, more particularly, to anchors for securing a therapy deliverydevice (e.g., a catheter) within, or otherwise relative to, a bodyportal such as a cranial burr hole, and to systems and methodsincorporating and using the same.

BACKGROUND

Medical procedures involving access to the brain through a burr hole inthe skull are used to treat a variety of medical conditions. Forexample, electrical stimulation of the brain to relieve chronic pain, orfor the treatment of movement disorders, may necessitate access via aburr hole. Similarly, burr holes are typically formed to allowimplantation of a therapy catheter, e.g., an intraparenchymal (IPA) orintracerebroventricular catheter, to treat various ailments.

Use of a catheter to deliver a therapeutic agent to the brain generallyinvolves the insertion of the catheter into the brain and dispensing theagent at the desired location. During a typical implantation procedure,an incision may be made in the scalp to expose the patient's skull.After forming a burr hole through the skull, the catheter may beinserted into the brain. To accurately place the catheter and avoidunintended injury to the brain, surgeons typically use stereotacticapparatus/procedures. One exemplary stereotactic apparatus is describedin U.S. Pat. No. 4,350,159 to Gouda (incorporated herein by reference inits entirety), which may be used to position, for example, an electrode.

As one can appreciate, once an inserted device such as a catheter isproperly positioned, it is important that it be adequately immobilizedto prevent movement of its distal, therapy delivering tip from itsintended location. Even minimal movement of the device tip may reducetherapeutic efficacy of some therapies. Accordingly, reliable methodsand apparatus for anchoring and securing the device relative to the burrhole are desirable.

In typical implantations, a free or connecting end of the device (e.g.,an IPA therapy catheter) may extend outside of the burr hole and beanchored, relative to the burr hole, with an anchoring device. The freeend of the therapy catheter may then be tunneled beneath the skin andconnected away from the anchor to a secondary or delivery catheter(e.g., via a connector pin) that is, in turn, coupled to a therapeuticsource containing the therapeutic agent. As a result, the agent may bedelivered through the delivery catheter and the therapy catheter to thedesired location within the patient.

During and after implantation, various forces may act on the deliverycatheter. These forces may occur as a result of certain bodily movements(e.g., neck movements, forces transmitted through the scalp, etc.) orfrom tissue-induced movement (e.g., tissue swelling). These forces maycause the delivery catheter to flex and/or pull relative to theconnector pin. Depending on how securely the connector pin is anchored,such forces may ultimately be transmitted to the therapy catheter. Ifsufficient, these forces may undesirably shift the therapy catheter, andthus its therapy delivery tip, away from the intended location.

SUMMARY

The present invention may overcome these and other issues by providing,in one embodiment, a body portal anchor system including: a baseoperable to secure to tissue surrounding a body portal; and a connectorselectively attachable to the base. The connector, when attached to thebase, is operable to fluidly connect with a terminal segment of atherapy catheter associated with the base. The system also includes aretaining member movable, relative to the base, between: a disengagedposition, wherein the retaining member is spaced-apart from theconnector so that the connector may move relative to the base; and anengaged position, wherein the retaining member engages the connector andattaches the connector to the base.

In another embodiment, an infusion system is provided including: atherapy catheter defining a lumen; and a burr hole anchor. The burr holeanchor includes an annular base defining a central opening and an outerperipheral edge. The base is operable to secure to bone surrounding aburr hole. The base further defines a catheter connection channelextending from the central opening outwardly through the peripheraledge. The anchor further includes a tubular connector selectivelyinsertable into the channel, wherein the connector includes a therapytip such that, when the connector is fully inserted into the channel,the therapy tip is received within the lumen of the therapy catheter. Aretaining member is also provided and positionable within an openingformed in the base, wherein the opening intersects the channel. Theretaining member is movable within the opening, while the connector isfully inserted into the channel, between: a disengaged position, whereinthe retaining member is spaced-apart from the connector; and an engagedposition, wherein the retaining member passes through the channel suchthat the retaining member contacts the connector and immobilizes theconnector relative to the base.

-   -   In yet another embodiment, a method for connecting an        intra-cranial therapy catheter implanted in tissue to a delivery        catheter is provided. The method includes: attaching a base of a        burr hole anchor to bone surrounding a burr hole; and        positioning a terminal segment of the therapy catheter within a        channel formed in the base. The method further includes:        inserting a connector into the channel until a therapy tip of        the connector is located within a lumen of the therapy catheter;        and positioning a movable retaining member in an engaged        position such that it contacts both the connector and the base        to secure the connector relative to the base.

The above summary is not intended to describe each embodiment or everyimplementation of the present invention. Rather, a more completeunderstanding of the invention will become apparent and appreciated byreference to the following Detailed Description of Exemplary Embodimentsand claims in view of the accompanying figures of the drawing.

BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING

The present invention will be further described with reference to thefigures of the drawing, wherein:

FIG. 1 is a diagrammatic perspective view of a therapy delivery systemin accordance with one embodiment of the invention, the systemincluding: a therapy source (e.g., an infusion pump); and an anchorsystem, an exemplary embodiment of which may include a body portalanchor (e.g., a burr hole anchor) and either or both of a deliverydevice (e.g., delivery catheter) and a therapy device (e.g., therapycatheter);

FIG. 2 is a partially exploded perspective view of the anchor of FIG. 1;

FIG. 3 is an enlarged perspective view of a connector and retainingmember of the anchor of FIG. 2;

FIG. 4 is a cross sectional view of the connector and retaining memberof FIG. 3 as assembled and viewed along a longitudinal axis of theconnector;

FIG. 5 is perspective view of the anchor of FIG. 2 with a connectorshown in an attached or fully inserted position and the retaining membershown in a disengaged position;

FIG. 6 is perspective view of the anchor of FIG. 5 with the retainingmember shown in an engaged position with the connector;

FIG. 7 is a partial cross sectional view of the anchor system of FIG. 1after implantation;

FIG. 8 is a top plan view of an anchor in accordance with anotherembodiment of the invention, wherein the anchor is show with a therapycatheter located therein;

FIG. 9 is a perspective view of the anchor of FIG. 8 with the therapycatheter trimmed to length, but before attachment of a connector anddelivery catheter;

FIG. 10 is an enlarged view of the connector of FIG. 9;

FIG. 11 is a perspective view of the anchor of FIG. 9 after attachmentof the connector to the therapy catheter and with a retaining membershown in a disengaged position;

FIG. 12 is a perspective view of the anchor of FIG. 11 after movement ofthe retaining member to an engaged position;

FIG. 13 is a top plan view of the anchor of FIG. 12;

FIG. 14 is a perspective view of the anchor of FIG. 12 with a capattached; and

FIG. 15 is a section view taken through the anchor of FIG. 14illustrating the interaction of the retaining member with the connector.

The figures are rendered primarily for clarity and, as a result, are notnecessarily drawn to scale.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the following detailed description of illustrative embodiments of theinvention, reference is made to the accompanying figures of the drawingwhich form a part hereof, and in which are shown, by way ofillustration, specific embodiments in which the invention may bepracticed. It is to be understood that other embodiments may be utilizedand structural changes may be made without departing from the scope ofthe present invention.

Embodiments of the instant invention may be directed to body portalanchor devices and assemblies and to corresponding body portal anchorsystems and methods for securing a therapy device such as a therapycatheter relative to a body portal. For example, exemplary anchorsdescribed herein may be configured to secure a therapy device such as anIPA therapy catheter routed through a cranial burr hole. Suchembodiments may further provide for connection of the therapy catheterwith a delivery catheter that is fluidly connected to a therapy source.

Unlike some conventional anchor systems, anchors and systems inaccordance with embodiments of the present invention may permitsubstantial isolation of the therapy catheter from forces that may actoutside of the body portal, e.g., forces acting upon the deliverycatheter. Moreover, systems, anchors, and methods in accordance withembodiments of the present invention may provide a catheter connectorthat may be selectively attached to the anchor during implantation(e.g., after the therapy catheter has been located). Such a constructionmay substantially reduce or prevent movement of the therapy catheter tipduring subsequent connection of the therapy catheter with the deliverycatheter. Various aspects of exemplary anchor devices, systems, andmethods are further described below.

While described herein in the context of burr hole anchors andcorresponding infusion systems, anchors and systems in accordance withembodiments of the present invention may find use in other medical (andnon-medical) applications that involve access through a portal.Moreover, while described herein with reference to a brain infusiontherapy catheter, embodiments of the invention may find application toother catheters and to other fluid conveying devices, as well as toother therapy devices, e.g., stimulation leads.

It is noted that the terms “comprises” and variations thereof do nothave a limiting meaning where these terms appear in the accompanyingdescription. Moreover, “a,” “an,” “the,” “at least one,” and “one ormore” are used interchangeably herein. Further, relative terms such asleft, right, forward, rearward, top, bottom, side, upper, lower,horizontal, vertical, and the like may be used herein and, if so, arefrom the perspective observed in the particular figure. These terms areused only to simplify the description, however, and not to limit thescope of the invention in any way.

FIG. 1 illustrates an exemplary implantable medical system, such as abrain infusion system 100 as it may be configured during use, e.g.,implantation. FIG. 1 is intended to be a diagrammatic representation ofan exemplary system. As a result, the illustration may not represent anactual scaled snapshot of the system during or after implantation.Embodiments of the components described herein may be sized for use withburr holes typical in human and other mammalian applications. Forexample, in one embodiment, a central opening 208 (see, e.g., FIG. 2)may be about 14 millimeters (mm) in diameter. However, such aconfiguration is not limiting as exemplary anchors could be scaled toaccommodate most any application without departing from the scope of theinvention.

The exemplary infusion system 100 may include an anchor system 201 witha first medical tube, e.g., an intra-cranial IPA therapy catheter 102,which may be partially implanted within a mammalian brain 116. To assistwith placement of the therapy catheter 102, a stereotactic apparatus asis known in the art may be utilized. In the illustrated example, thetherapy catheter 102 is implanted through a body portal, e.g., through aburr hole 110 (the burr hole is located underneath a burr hole anchor200 in FIG. 1; see FIGS. 2 and 7). The burr hole 110 may be formed intissue (e.g., the bone forming the skull 111, which is representeddiagrammatically in the figures), which is shown partially cut-away inFIG. 1 for clarity. Ultimately, once the catheter 102 is accuratelyimplanted through the burr hole in the skull, a second end or tip 108 ofthe catheter is positioned at a predetermined location within the brain116.

The infusion system (e.g., the anchor system 201) may further include asecond medical tube, e.g., a feed or delivery catheter 104. The deliverycatheter may have a second end 105 coupled to a therapy source orreservoir (e.g., an implantable infusion pump 106 such as a SynchroMed®II programmable infusion pump distributed by Medtronic, Inc., ofMinneapolis, Minn. USA) containing a volume of the therapeutic agent.While described herein in the context of an implantable infusion pump106, this configuration is not limiting. For example, other embodimentsmay replace the pump with most any internal or external medicamentdelivery device, e.g., syringe, drip bag, etc.

A first end 112 of the therapy catheter 102 may be routable through acranial burr hole anchor device or assembly (referred to herein as“anchor 200”). In the illustrated embodiment, the first end 112 of thetherapy catheter 102 may, via the anchor 200, be operatively connectedto a corresponding first end 114 of the delivery catheter 104 (e.g., viaa connector 204, exemplary embodiments of which may form a tubularmember as described below).

The infusion system 100 may, in one embodiment, be configured to delivera therapeutic agent for the treatment of a chronic ailment, e.g.,convection-enhanced delivery (CED) of a medicament for the treatment ofHuntington's disease. The therapeutic agent is delivered, via thecatheters 102 and 104, from the pump 106 to the brain 116. Thisapplication is not limiting, however, as the system may be configured todeliver other therapeutic agents (e.g., such as for the treatment ofParkinson's or Alzheimer's disease) to the brain or to most any otherregion of the body.

With this general overview, the following description will addressvarious exemplary embodiments and aspects of the anchor 200 and system201, as well as methods for using the same. While these embodiments maybe described with some degree of particularity, they are nonethelessintended to be exemplary. That is, those of skill in the art willrecognize that other embodiments are certainly possible.

FIG. 2 illustrates an enlarged perspective view of the anchor system201. As shown in this view, the anchor 200 may include an annular base202 that may be positioned to surround the burr hole 110, and anoptional cap 203. The anchor 200 (e.g., the base 202) may be operable tosecure to the tissue, e.g., to an outer surface of the skull (bone 111)surrounding the burr hole 110 via any acceptable method. In theillustrated embodiment, the base 202 is secured with bone screws (notshown) extending through openings (e.g., holes 206) formed through thebase 202. The system 201 may further include the tubular pin orconnector 204 selectively attachable to the base as further describedbelow.

The base 202 may define a central opening 208 that aligns coaxially withthe burr hole 110 when the base is attached to the bone 111. The annularbase 202 may further define an outer peripheral edge 210 and an uppersurface 212. In the illustrated embodiments, the base, e.g., the face212, may have a cutout or series of cutouts that define a catheterconnection passage, e.g., a shaped catheter connection channel 214extending from the central opening 208 outwardly to and through theperipheral edge 210. The channel 214 may, in the illustratedembodiments, be formed in the upper surface 212 of the base. Asdescribed in more detail below, the channel 214 may receive therein thefirst or terminal end 112 of the therapy catheter 102. A terminalsegment of the catheter 102 (the end segment of the catheter thatincludes the first end 112) may be received and mechanically captured inthe channel 214 by, in one embodiment, cinching surfaces 216 formed ordefined by the channel. In the illustrated embodiments, cinchingsurfaces 216 are included at two discrete locations (cinching points 218and 220). These surfaces may overhang portions of the channel asillustrated in the figures.

The channel 214 may be configured in most any acceptable manner thatprovides a passageway extending from the central opening 208 through theperipheral edge 210. However, in the illustrated embodiment, the channel214 is configured as a relatively open-faced trough as shown in FIG. 2.As visible in this view, the channel 214 may be further defined by firstand second enlarged areas 222 and 224. The purpose of the enlarged areas222 and 224 is explained in more detail below.

In addition to receiving the catheter 102, the trough-like channel 214may also receive therein the connector 204. As illustrated in thefigures, the connector 204 may include a first end 226 defining atherapy tip for selective insertion into the channel 214, and anopposite or second end 228 defining a delivery tip. The connector 204may further include an enlarged central portion 230 between the firstand second ends. The first and second ends 226, 228 (e.g., the therapytip and the delivery tip) may be configured for insertion into lumensof, respectively, the therapy catheter 102 and the delivery catheter104. The shape and size of the first and second ends of the connector204, as well as the size and material of the catheters, may be selectedto produce a relatively secure and leak-free connection between thecatheters and the connector when joined.

The system 201 may further include a retaining element or member, whichin one embodiment, is configured as a detachable clip 232. The retainingmember may be configured to engage the connector 204 and immobilize itrelative to the base 202 after the connector is inserted into thechannel 214 and the therapy catheter 102. While shown as a separatecomponent in FIGS. 1-7, the retaining member could, in otherembodiments, be integral to, or retained by, the connector (e.g.,threads or pins) or, alternatively, integral with or retained by theanchor base 202. In fact, the retaining member may be of most anyconfiguration that allows selective, clinician-initiated fixing of theconnector relative to the base.

As used herein, the term “immobilize” and its variations refers tosecuring a first member to one or more second members such that littleor no relative movement occurs between the first and second members.Those of skill in the art will realize that, for a variety of reasons(e.g., tolerances of parts), some minor relative movement may stilloccur between the members, but such movement is minimized and of littleor no consequence to the intended operation of the immobilized member.

The cap 203 may include one or more elements, e.g., tabs 234, whichinteract with receiving elements, e.g., slots 236, formed in the base topermit snap-fit engagement of the cap to the base. The cap 203 mayfurther include a slot or opening 238 to permit removal of the cap, e.g.via a prying action, from the base if desired.

While most any biocompatible material is suitable, the base 202 and cap203 may, in one embodiment, be made from a hard plastic (e.g.,polysulfone or polyetheretherketone (PEEK)) or metal such as grade 2 orgrade 5 Titanium. The connector 204 and retaining clip may be made ofthe same or similar materials.

The catheter 102 may, in one embodiment, be similar or identical to thecatheters described in U.S. Pat. App. Pub. 2009/0143764 A1 to Nelson andentitled INFUSION CATHETER ASSEMBLY WITH REDUCED BACKFLOW (incorporatedherein by reference in its entirety). In other embodiments, the catheter102 (as well as the catheter 104) may be of conventional constructionand made from most any shearable material including, e.g., urethane,silicone, or blends of the same.

FIG. 3 illustrates an enlarged perspective view of the connector 204 andthe clip 232 with the latter in a disengaged or detached position. Asshown in this view, the enlarged central portion 230 of the connector204 may include cutouts to receive the clip. For instance, an outersurface of the central portion 230 may include a circumferential groove240 and an intersecting longitudinal groove 242. The circumferentialgroove 240 may be sized to partially receive therein two opposingresilient legs 244 of the clip, e.g., in a snap-fit relation. In theillustrated embodiment, the legs 244 are semi-cylindrical in shape tocorrespond with the shape of the groove 240. In a similar manner, thegroove 242 may receive a body portion 246 of the clip. The body portion246 may form a key or other anti-rotate feature configured to limitrotational movement of the connector and clip relative to the base whenthe connector is fully inserted into the channel 214 and the clip isplaced in the engaged or attached position (see, e.g., FIG. 4). In theillustrated embodiment, this anti-rotate feature is achieved byproviding corresponding keyway surfaces in the channel 214. The bodyportion 246 may also prevent rotation of the clip 232 relative to theconnector 204 by fitting into the groove 242 of the connector.

FIG. 4 is a section view of the connector 204 and clip 232 taken normalto a longitudinal axis 250 (see FIG. 2) of the connector/channel andthrough the groove 240 when the clip is attached to the connector. FIG.4 further illustrates a cutout 248 that may be formed in the clip, aswell as the delivery lumen of the connector (which extends entirelythrough the connector). The cutout may accommodate a tool to pry theclip 232 and separate it from the connector when removal of theconnector from the base 202 is desired. The clip 232 and/or connector204 could also include features that permit attachment, e.g., tethering,to the anchor base 202 as a means of preventing the clip from being lostduring attachment and detachment.

Use of the exemplary anchor system 201 will now be described withreference primarily to FIGS. 2 and 5-7. The intra-cranial therapycatheter 102 may be correctly positioned through the burr hole 110(already formed) such that the implanted therapy delivering tip 108 (seeFIG. 1) is located at the desired location within the brain 116. Asstated above, stereotactic equipment and methods as are known in the artmay be utilized to locate the catheter 102. The base 202 may typicallybe attached to the skull bone before catheter implantation. The therapycatheter may then be routed through the central opening 208 of the base202 using the stereotactic apparatus, often with the aid of guidecannula and/or stylet. The base could also be attached after catheter102 implantation. In this instance, the catheter 102 could be detachedfrom the stereotactic apparatus and the anchor base 202 placed over thecut catheter (i.e., the exposed end of the catheter may be passedthrough the central opening) and attached to the skull. In alternateembodiments, the anchor base 202 could be slotted (e.g., C-shaped) toallow side-loading attachment during, before, or after placement (e.g.,stereotactic placement) of the catheter 102.

The catheter may then be bent to pass through and lie within the channel214 as shown in FIG. 2. With the trough-like channel 214 of theillustrated embodiment, the terminal segment of the therapy catheter maybe pressed into the channel from above, e.g., the catheter 102 may enterthe channel in a direction transverse or normal to the longitudinal axis250 of the channel. As the catheter 102 is pressed into the channel, itmay ultimately squeeze past the opposing cinching surfaces 216 at boththe first and second cinching points 218 and 220. The cinching surfaces216, as illustrated herein, are configured as an overhang over thechannel 214 as best shown in FIGS. 2 and 5. This overhang may provide anarrow entry for the catheter into the channel 214. However, beyond theoverhang, the channel may be of sufficient width to accommodate thecatheter with a clearance fit.

While described herein as overhanging, the cinching surfaces 216 may beof most any design that permits mechanical capture of the catheter oncethe catheter is fully inserted into the channel, e.g., any design thatlimits movement of the catheter in at least the transverse direction (ina direction other than along the longitudinal axis 250 of the connector)back out of the channel. Regardless of the configuration, the channel214 may effectively receive and contain the terminal segment of thetherapy catheter 102 within the channel at one or more discretelocations (e.g., in the illustrated embodiment, at the two cinchingpoints 218 and 220).

While described herein as utilizing mechanical capture elements orcinching surfaces, these aspects of the invention are optional. That is,alternative embodiments may do away with the overhanging cinchingsurfaces altogether. In such a configuration, a compliant catheter maysimply be bent wherein it lies within a generally open channel. In thiscase, the catheter 102 could be held in place by a surgical instrumentduring the catheter connection process.

An unneeded, excess length or portion 113 of the catheter may nowprotrude outwardly from the outermost cinching point 220 as shown in thebroken line representation in FIG. 2. To remove this excess portion 113from the terminal segment of the catheter 102, the clinician may insertforceps or the like (not shown) into the first enlarged area 222 of thechannel 214 to hold the catheter 102 while surgical scissors or ascalpel (not shown) are used to sever the excess portion 113. In theillustrated embodiment, the second enlarged cutout 224 is defined inpart by a cut surface 225 (the cut surface may be adjacent one or moreof the cinching surfaces in the illustrated embodiment) that may be usedas a guide to trim the catheter 102. That is, the catheter 102 may becut in the second enlarged area along the cut surface 225. Aftertrimming and removing the excess portion 113 that extends beyond the cutsurface 225, the resulting first end 112 of the catheter may be locatedwithin the channel 214 at or near the cut surface as shown in FIG. 2.

With the therapy catheter 102 now cut to length and positioned in thechannel 214, the lumen of the therapy catheter is aligned with thechannel and thus aligned with the first end of the connector 204.Accordingly, as the connector 204 is inserted into the channel 214, thetherapy tip of the first end 226 of the connector may enter the lumen ofthe catheter 102, at which point the connector may be fluidly connectedwith the terminal segment of the catheter. In one embodiment, theconnector 204 may be selectively inserted through a feed connector port249 of the base 202 and along the longitudinal axis 250 as indicated bythe arrow 252 in FIG. 2. In this embodiment, the channel 214 may beconfigured to limit movement of the connector 204 along generally allbut the direction 252 (i.e., the channel may allow movement of theconnector generally only along the longitudinal axis 250). Moreover, thefeed connector port 249 may also be configured to restrict insertion ofthe connector to only the longitudinal direction, e.g., it may have aconfiguration that does not allow the connector to pass into the channelfrom above. While inserting the connector 204 into the channel 214, thecatheter 102 may again be gripped with forceps or the like positionedwithin the first enlarged area 222. As illustrated in the figures, thefirst (and second) end of the connector 204 may have a shape conduciveto insertion into the catheters, e.g., be conically shaped, radiused, orbeveled to permit the ends of the connector to more easily enter therespective catheters.

Continued insertion of the connector 204 into the channel 214 mayeventually result in contact between an annular face 254 (see FIG. 3) ofthe connector and the cut surface 225 of the base 202. This contact maylimit further insertion of the connector into the channel as shown inFIG. 5. When the connector is fully inserted into the channel as shownin FIG. 5, the annular face 254 of the connector 204 may abut not onlythe cut surface 225, but also abut, or nearly abut, the first end 112 ofthe therapy catheter 102.

Once the connector 204 is fully inserted into the channel 214 and thecatheter 102, the retaining member, e.g., clip 232, may be moved fromthe disengaged position (see, e.g., FIGS. 2, 3 and 5) to an engagedposition (see, e.g., FIGS. 4 and 6) to secure the connector relative tothe base 202. When in the disengaged position, the retaining member 232may be spaced-apart from the connector 204 to allow movement of theconnector relative to the base, e.g., within the channel or passage.However, when in the engaged position, the retaining member 232 engagesthe connector 204 and immobilizes it relative to the base 202.

To attach the clip 232 to the anchor, the clip (e.g., while held byforceps or the like) may be pressed onto the connector with sufficientforce that the resilient legs 244 (see FIGS. 3 and 4) expand and thenretract around the round portion of the connector within thecircumferential groove 240. As evident in the figures, the clip 232 mayengage the connector 204 (e.g., move from its disengaged to engagedpositions) along a direction transverse or normal to the longitudinalaxis 250. Once fully inserted into the groove 240, the clip 232mechanically captures the connector 204 relative to the base 202, i.e.,once the clip 232 is attached to the connector 204, the connector iseffectively attached or fixed to the base. In the illustratedembodiment, the portions of the clip 232 that protrude beyond the outerdiameter of the connector 204 may be accommodated by the second enlargedarea 224. As also shown in FIG. 6, the clip 232 and annular face 254 ofthe connector 204 (see FIG. 3) may be restrained within the secondenlarged opening 224, e.g., restrained between the cut surface 225 and astop surface 227 defined by the second enlarged opening. As a result,axial movement of the connector 204 is substantially limited.

Similarly, the body portion 246 of the clip 232 (see FIGS. 3 and 6) mayseat within a narrow slot 251 (see also FIG. 2) formed in the top of thefeed connector port 249, as well as within the longitudinal groove 242of the connector 204. By nesting within the slot 251, the body portion246 may limit rotational movement of the connector relative to the base202.

With the connector secured in the channel 214, the cap 203 (see FIG. 2)may be attached to the base 202 to cover the central opening 208 asdescribed elsewhere herein. The first end 114 of the delivery catheter104 (see FIGS. 1 and 6) may then be attached to the delivery tip (thesecond end 228) of the connector 204 by inserting the second end 228into the catheter 104 until the catheter abuts a second annular face 256of the connector (see FIGS. 3 and 6). The delivery catheter 104 may becoupled, as illustrated in FIG. 1, at its second end 105 to the pump 106or other therapeutic source. In other embodiments, the delivery catheter104 (see FIG. 1) could be attached to the connector 204 before theconnector is attached to the base 202.

As stated elsewhere herein, due to the mechanical capture of theconnector 204 to the base 202, the transmission of extraneous loads tothe therapy catheter 102 from the delivery catheter 104 may besubstantially reduced or eliminated.

FIG. 7 illustrates a section view of the assembled anchor system 201after catheter interconnection and surgical implantation. As clearlyshown in this view, the anchor base 202 is aligned over the burr hole110 and secured to the skull 111 as described herein. With the basesecured, the catheters 102 and 104 connected, and the cap 203 installed,the surgical incision in the skin 115 (made to access the skull 111) maybe closed and the infusion system operated in accordance with thedesired therapy delivery profile. Those of skill in the art will realizethat the various components (e.g., catheters 102 and 104 and pin 204) ofthe system may be primed or otherwise purged of air prior to therapyinitiation.

While illustrated in FIGS. 1-7 as providing an anti-rotate feature, theretaining member, e.g., clip 232, may, in another embodiment, beprovided without such features. For example, the clip could be formedgenerally as a C-shaped member such that it includes the resilient legs244 but not the body portion 246 as shown in FIG. 3. Such a clipembodiment could be provided where rotation of the catheters 102, 104 isrestrained by another mechanism or is otherwise not of particularimportance to the operation of the system.

FIGS. 8-15 illustrate a body portal (e.g., burr hole) anchor system 301including an anchor (e.g., burr hole anchor 300) in accordance with yetanother embodiment of the present invention. The anchor 300 is, as isevident from this description, similar in many respects to the anchor200 and, in fact, may be substituted for the anchor 200 and vice-versa.For brevity, description of aspects of the anchor 300 that are common orsimilar to the anchor 200 (e.g., the catheters 102, 104, cap 203,aspects of the base 302, etc.) may not be repeated herein.

Although similar in many ways to the anchor 200 (e.g., the anchor 300has a base 302 and a tubular connector 304 selectively attachable to thebase), the system 301/anchor 300 may utilize a retaining member 332 thatis captivated by the base 302. By captivating the retaining member 332,the anchor 300 may offer various benefits over non-captivatedconfigurations. For example, the retaining member 332 may beautomatically aligned relative to the base 302 prior to engagement withthe connector 304, easing the engagement process. Moreover, thecaptivated retaining member 332 is not susceptible to being lost ormisplaced before or during implantation. Still further, this embodimentdirectly keys to and aligns with the connector 304, eliminating the needto orient a keying feature on the retaining member before attachment.

FIG. 8 is a top plan view of the annular base 302 of the anchor 300. Asshown in this view, the base 302 may, like the base 202, include acatheter connection passage (which, in the illustrated embodiment, is atrough-like, recessed catheter connection channel 314 formed in a uppersurface of the base) extending from its central opening 308 radiallyoutward to and through its outer peripheral edge 310. Unlike the base202, however, the outer peripheral edge 310 may have inwardly notchedareas 311 on each side of the channel 314 to provide access to theretaining member 332 as further described below. While illustrated ashaving notched areas 311, alternative embodiments may maintain the roundedge of the base, but permit the area in and around the channel 314 toextend radially outwardly beyond the round peripheral edge.

As shown in FIGS. 8 and 9, the captive retaining member 332 may beformed as an elongate member or pin that is positionable (e.g., slidesor translates within) an opening 333 formed in the base 302 betweendisengaged and engaged positions. The opening 333 may intersect thechannel 314 such that the retaining member 332 may pass through (e.g.,across) the channel as further described below. In one embodiment, theopening 333 and retaining member 332 extend completely through thechannel in a direction transverse to a longitudinal axis 350 of thechannel/connector 304 as shown. However, other orientations of theretaining member 332 are certainly possible without departing from thescope of the invention.

Once the therapy catheter 102 is positioned and the base 302 is securedto tissue (e.g., bone 111) in a manner as already described herein withrespect to system 201, the terminal segment of the therapy catheter 102may be positioned within the channel 314 where it is held in place bycinching surfaces 316 (e.g., at cinch points 318 and 320) that at leastpartially overhang and define the channel. The cinching surfaces aresimilar in form and function to the cinching surfaces 216 alreadydescribed herein. The catheter 102 may then be cut to length in a mannersubstantially similar to that described with respect to anchor 200(e.g., the catheter 102 may be held with forceps or the like via a firstenlarged area 322 of the channel 314, while a surgical cutting tool isused to cut the catheter along a cut surface 325 formed in a secondenlarged area 324). With the therapy catheter 102 cut to the appropriatelength, as shown in FIG. 9, the connector 304 (either with or withoutthe delivery catheter 104 attached) may be selectively insertedlongitudinally into the channel 314 as indicated. The delivery catheter102 may be held via the first enlarged area 322 while the connector 304is introduced.

FIG. 10 illustrates a bottom perspective view of the exemplary connector304. Like the connector 204, the connector 304 may include a first end326 defining a therapy tip for selective insertion into the channel 314,and an opposite or second end 328 defining a delivery tip. The connector304 may further include an enlarged central portion 330 between thefirst and second ends. The first and second ends 326, 328 (e.g., thetherapy tip and the delivery tip) may be configured for insertion intothe lumens at first ends of, respectively, the therapy catheter 102 andthe delivery catheter 104 when the connector 304 is fully inserted intothe channel 314. Like the catheters of the system 201, the second end ofthe therapy catheter 102 may be located at the desired target sitewithin the body, while the second end of the delivery catheter 104 maybe connected to a therapy source (see, e.g., implantable infusion pump106 illustrated in FIG. 1).

The enlarged central portion 330 of the connector 304 may include acutout or slot. For instance, an outer surface of the central portion330 may include a groove 340 that extends transverse to the longitudinalaxis 350 of the connector. The groove 340 may be sized to receive atleast a portion of the retaining member 332 when the latter is moved toan engaged position (and when the connector 304 is fully inserted intothe channel 314 as further described below). The groove 340 isconstructed to ensure that it does not intersect the lumen of theconnector 304.

The central portion 330 may further define a longitudinal protrusion orridge 335 running along a portion, e.g., a top edge, of the centralportion. The ridge 335 may slide between anti-rotate keyway surfaces ofthe channel 314, thereby forming an anti-rotate key or the like to limitrotational movement of the connector 304 relative to the base 302. Inaddition to acting as an anti-rotate keyway, the ridge 335 also assistswith aligning the groove 340 with the retaining member 332.

As the connector 304 is inserted into the channel 314, the therapy tip326 may enter the lumen of the therapy catheter 102. During insertion,the therapy catheter 102 may be held in place with forceps or the likegripping the catheter via access through the first enlarged area 322 ofthe base. Alternatively, the channel may include other features thatrestrict longitudinal movement of the catheter 102. Eventually, anannular face 356 (see FIG. 10) of the connector 304 may contact the cutsurface 325 of the base 302 (see FIG. 11) defined by a face of thesecond enlarged area 324. The cut surface 325 may limit furtherinsertion of the connector into the channel. That is, the base 302 andconnector 304 are configured such that, when this contact occurs, theconnector is fully inserted into the channel 314 such that the groove340 of the connector 304 (see FIG. 10) is aligned with the retainingmember 332 (see FIG. 11).

The retaining member 332 may be movable within the opening 333, when theconnector is full inserted into the channel 314, between: a first ordisengaged position as shown in FIG. 11; and a second or engagedposition as shown in FIGS. 12-14. In the disengaged position, theretaining member 332 lies outside of the channel 314 (or protrudes onlyslightly into the channel). That is, in the disengaged position, theretaining member 332 is spaced-apart from the connector 304 (while theconnector is being inserted (or is fully inserted) into the channel 314)such that the retaining member does not interfere with movement of theconnector relative to the base (does not interfere with movement of theconnector within the channel). The retaining member 332 and opening 333may, in the illustrated embodiment, be rectangular (e.g., square) incross section (with the groove 340 providing a complimentary shape).However, other shapes are possible within the scope of the invention.

However, once the connector 304 is fully inserted (e.g., once theannular face 356 of the connector 304 (see FIG. 10) contacts the cutsurface 325 (see FIG. 11) of the channel 314), the clinician maymanually actuate the retaining member 332 by applying a force to abutton end 337. As this force is applied, the retaining member 332 maymove from the disengaged position (see FIG. 11) to the engaged position(see FIG. 12). This causes the retaining member 332 to extend or passthrough the channel 314 and into the aligned groove 340 (see FIG. 10)formed in the connector 304. When fully depressed as shown in FIGS. 12and 13, a distal end 339 of the retaining member 332 may protrude beyondan opposite side of the base 302. Accordingly, when moved to the engagedposition, the retaining member 332 engages or contacts the connector 304(as well as the base 302) and immobilizes the connector relative to thebase (e.g., the retaining member 332 effectively attaches the connectorto the base).

When the connector 304 is fully inserted into the base 302 as shown inFIGS. 12 and 13, the ridge 335 of the connector may be captivatedagainst rotation by surfaces of the base 302 that form the channel 314.As a result, the connector 304 (and thus the catheters 102 and 104) isgenerally restricted from rotation relative to the base 302.

As further shown in FIG. 13, the distal end 339 of the retaining member332 may include a tab 341 or the like. The tab 341 may protrudesufficiently to prevent the retaining member 332 from moving from itsengaged position back towards the disengaged position, thus providingpositive locking or capture of the retaining member when in the engagedposition. In the illustrated embodiment, the tab 341 may have a rampedor rounded nose to permit it to push easily through the opening of thebase 302 as the retaining member is moved towards the engaged position.

Moreover, the distal end 339 of the retaining member 332 may include aslot 343 as shown in FIG. 13. The slot may permit the tab 341 of theretaining member 332 to deflect. As a result, the tab 341 may travelwithin the opening 333 formed through the base 302 when the retainingmember is moved towards the engaged position. However, the tab mayresiliently return to its undeflected position shown in FIG. 13 upon theretaining member reaching the engaged position. The tab 341 and slot 343may also prevent the retaining member from sliding out of the base 302when the retaining member is in the disengaged position (e.g., as shownin FIG. 8, the tab may keep the distal end 339 from sliding out (beyondthe disengaged position) by captivating the tab 341 within the channel314).

Once the retaining member 332 is engaged with the connector 304 asdescribed herein, the connector may be immobilized relative to the base302. As a result, extraneous forces acting on the therapy catheter 104may be isolated by the connector such that they transfer little or nodisplacement loads to the therapy catheter 102.

FIG. 14 illustrates the anchor 300 after attachment of the exemplary cap203, which may attach to the base 302 in a manner substantially similarto the base 202 described above.

FIG. 15, illustrates a section view of the anchor of FIG. 14. In thisview, the base 302, catheters 102, 104, connector 304, and retainingmember 332 are visible with the retaining member shown in the engagedposition and the connector shown fully inserted into the channel 314. Asshown in this view, the connector 304 may fluidly couple to both theterminal segment of the therapy catheter 102 and the delivery catheter104, permitting fluid conveyance from the delivery catheter to thetherapy catheter.

Once again, while illustrated herein in the context of specificexemplary embodiments, variations are certainly possible withoutdeparting from the scope of the invention. For example, whileillustrated with only a single delivery catheter 104 and therapycatheter 102, other embodiments may utilize additional delivery and/ortherapy catheters where beneficial to the specific application.

Anchors and systems in accordance with embodiments of the presentinvention may provide various benefits including, for example, isolatingthe therapy catheter from forces that may otherwise be transmittedthereto by the delivery catheter. As a result, the delivering tip of thetherapy catheter may be less likely to be displaced during theimplantation period. Further, for example, anchors in accordance withembodiments of the present invention permit attachment of the catheterconnector to the anchor base after the base has been attached to tissueand after the therapy catheter has been positioned.

Illustrative embodiments of this invention are discussed and referencehas been made to possible variations within the scope of this invention.These and other variations, combinations, and modifications in theinvention will be apparent to those skilled in the art without departingfrom the scope of the invention, and it should be understood that thisinvention is not limited to the illustrative embodiments set forthherein. Accordingly, the invention is to be limited only by the claimsprovided below and equivalents thereof.

1. A body portal anchor system comprising: a base operable to secure to tissue surrounding a body portal; a connector selectively attachable to the base, wherein the connector, when attached to the base, is operable to fluidly connect with a terminal segment of a therapy catheter associated with the base; and a retaining member movable, relative to the base, between: a disengaged position, wherein the retaining member is spaced-apart from the connector so that the connector may move relative to the base; and an engaged position, wherein the retaining member engages the connector and attaches the connector to the base.
 2. The system of claim 1, wherein the base defines a catheter connection passage configured to receive both the terminal segment of the therapy catheter and a first end of the connector.
 3. The system of claim 2, wherein the passage forms a trough-like channel in an upper surface of the base, the channel partially covered by overhanging cinching surfaces.
 4. The system of claim 2, wherein the retaining member comprises a pin translatable within an opening formed in the base, the pin configured to engage a slot formed in the connector when the connector is inserted into the passage and the retaining member is in the engaged position.
 5. The system of claim 2, wherein the connector comprises: the first end adapted for insertion into both the passage and a lumen of the therapy catheter; and a second end adapted for insertion into a lumen of a delivery catheter.
 6. The system of claim 2, wherein either the retaining member or the connector comprises an anti-rotate key configured to limit rotational movement of the connector relative to the base when the connector is inserted into the passage and the retaining member is in the engaged position.
 7. The system of claim 2, wherein the passage is configured to limit movement of the connector along all but a direction parallel to a longitudinal axis of the passage.
 8. The system of claim 2, wherein the base defines a central opening and wherein the passage extends from the central opening outwardly through a peripheral edge of the base.
 9. The system of claim 8, further comprising a cap, the cap attachable to the base to cover the central opening.
 10. The system of claim 1, wherein the retaining member moves along a direction transverse to a longitudinal axis of the connector as the retaining member moves between the disengaged and engaged positions.
 11. The system of claim 1, wherein the retaining member comprises opposing resilient legs configured to be received partially within a circumferential groove formed in an outer surface of the connector.
 12. An infusion system comprising: a therapy catheter defining a lumen; and a burr hole anchor comprising: an annular base defining a central opening and an outer peripheral edge, the base operable to secure to bone surrounding a burr hole, wherein the base defines a catheter connection channel extending from the central opening outwardly through the peripheral edge; a tubular connector selectively insertable into the channel, wherein the connector comprises a therapy tip such that, when the connector is fully inserted into the channel, the therapy tip is received within the lumen of the therapy catheter; and a retaining member positionable within an opening formed in the base, the opening intersecting the channel, wherein the retaining member is movable within the opening, while the connector is fully inserted into the channel, between: a disengaged position, wherein the retaining member is spaced-apart from the connector; and an engaged position, wherein the retaining member passes through the channel such that the retaining member contacts the connector and immobilizes the connector relative to the base.
 13. The system of claim 12, wherein the base comprises a surface configured to limit insertion of the connector into the channel.
 14. The system of claim 12, wherein the channel is at least partially defined by cinching surfaces configured to mechanically capture a terminal segment of the therapy catheter.
 15. The system of claim 14, wherein the cinching surfaces mechanically capture the terminal segment of the therapy catheter at two discrete locations along the terminal segment.
 16. The system of claim 12, further comprising a delivery catheter including a first end configured to attach to a delivery tip of the connector, and a second end configured to attach to a therapy source.
 17. The system of claim 16, wherein the therapy source comprises an infusion pump.
 18. A method for connecting an intra-cranial therapy catheter implanted in tissue to a delivery catheter, the method comprising: attaching a base of a burr hole anchor to bone surrounding a burr hole; positioning a terminal segment of the therapy catheter within a channel formed in the base; inserting a connector into the channel until a therapy tip of the connector is located within a lumen of the therapy catheter; and positioning a movable retaining member in an engaged position such that it contacts both the connector and the base to secure the connector relative to the base.
 19. The method of claim 18, further comprising inserting a delivery tip of the connector into a lumen of the delivery catheter.
 20. The method of claim 18, wherein positioning the retaining member comprises translating the retaining member within an opening of the base from a disengaged position to the engaged position.
 21. The method of claim 18, further comprising trimming an excess length of the therapy catheter from the terminal segment while the terminal segment is positioned within the channel.
 22. The method of claim 18, wherein inserting the connector into the channel comprises inserting the connector along a longitudinal axis of the channel.
 23. The method of claim 22, further comprising limiting movement of the connector, while the connector is being inserted into the channel, to only movement along the longitudinal axis.
 24. The method of claim 18, further comprising limiting rotational movement of the connector relative to the base when the retaining member is in the engaged position. 